Variable lordotic interbody spacer

ABSTRACT

A variable lordotic interbody spacer including a face plate, superior and inferior endplates coupled to the face plate via a hinge, an actuation frame between the endplates, and an actuation screw. The face plate includes actuation and stabilizer channels. Each of the endplates has endplate arms coupled by an endplate base, and includes actuation ramp recesses. The actuation frame includes frame arms coupled by a frame base in a generally U-shaped configuration, each actuation frame arm having a stabilizer feature passing through a corresponding stabilizer channel and having actuation ramp pins fitted to a corresponding ramp recesses. The actuation screw passes through the actuation channel, with a head retained at the front surface and a threaded end coupled to the actuation frame. When operated, the actuation screw moves the actuation frame between the superior endplate and the inferior endplate to adjust an angle therebetween.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of patentapplication Ser. No. 16/513,913, filed on Jul. 17, 2019 (published asU.S. Pat. Pub. No. 2019-0358049), which is a divisional application ofpatent application Ser. No. 15/817,793, now U.S. Pat. No. 10,390,964,which is a continuation application of U.S. patent application Ser. No.14/741,939 filed on Jun. 17, 2015, now U.S. Pat. No. 9,848,996, each ofwhich are hereby incorporated by reference in their entireties for allpurposes.

FIELD OF THE INVENTION

The present invention relates to intervertebral disc prostheses, andmore particularly to a lordotic interbody spacer that is adjusted orexpanded in situ to occupy desired space between vertebral bodies.

DESCRIPTION OF THE RELATED ART

Spinal fusion is a surgical technique used to facilitate the growth ofbone between two vertebrae. The procedure involves implanting a spacer,such as an interbody device, for example, packed with grafting materialinto the disc space to stabilize the spine while bone grows in betweentwo vertebrae. As the bone graft material heals, one long bone is formedwith the adjacent vertebrae. The purpose is to eliminate movementbetween the vertebrae to reduce pain and nerve irritation.

An interbody fusion may involve removing the intervertebral disk. Whenthe disk space has been cleared, the interbody device is implantedbetween the two adjoining vertebrae. These devices may contain the bonegraft material that promotes bone healing and facilitates the fusion.After insertion, surgeons may use (e.g., bone) screws, plates, and rodsto further stabilize the spine. Interbody fusion can be performed usinga variety of different approaches, and, in an anterior lumbar interbodyfusion, the procedure is performed from the front of the patient.

Lordotic angle is the angle between the top (superior surface) of thesecond lumbar vertebra and the bottom (inferior surface) of the fifthlumbar vertebra, used as a measurement of the curve of the lumbar spine.In some instances, it might be desirable to adjust or otherwise set thelordotic angle during the spinal fusion operation to adjust lordosis ofthe spine.

SUMMARY OF THE INVENTION

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

In one embodiment, the present invention enables a spinal fusiontreatment with a variable lordotic interbody spacer including: a faceplate, superior and inferior endplates, an actuation frame, and anactuation screw. The face plate includes a front surface and a rearsurface, the face plate further having at least one actuation channeland at least two stabilizer channels formed through the face plate fromthe front surface to the rear surface. Each of the superior and inferiorendplates has first and second endplate arms coupled by a base in agenerally U-shaped configuration, each endplate arm coupled to the rearsurface of the face plate via a hinge opposite from the base. Eachendplate arm includes a ramp recess on a top surface and on a bottomsurface. The actuation frame is positioned between the superior endplateand the inferior endplate, the actuation frame having first and secondframe arms coupled by a frame base in a generally U-shapedconfiguration, each actuation frame arm having a stabilizer featureopposite from the frame base and configured to pass through acorresponding stabilizer channel, the actuation frame further includinga receptacle formed at the inside of the frame base. Each frame armincludes an actuation ramp pin on a top surface and on a bottom surfacefitted to a corresponding ramp recess. The actuation screw includes ahead, body and threaded end, the actuation screw body passing throughthe actuation channel, the head retained at the front surface and thethreaded end threadably coupled to the receptacle of the actuationframe. When operated, the actuation screw moves the actuation framebetween the superior endplate and the inferior endplate to adjust anangle there between.

According to another embodiment, a method of treatment includesinserting or implanting the variable lordotic interbody spacer in a discspace between adjacent vertebrae. The variable lordotic interbody spacermay be inserted in a collapsed or closed position, for example. Onceimplanted into the disc space and seated at the appropriate position,the variable lordotic interbody spacer may be moved or enlarged to anexpanded or open position. In particular, the position of the variablelordotic interbody spacer may be expanded to adjust the position of apatient's lordosis via adjustment of the lordotic angle in situ duringan interbody fusion operation. It is contemplated that one or more thanone variable lordotic interbody spacers or other fusion devices can beinserted in the intervertebral space. It is further contemplated thateach variable lordotic interbody spacer does not have to be finallyinstalled in the fully expanded state. Rather, depending on the locationof the variable lordotic interbody spacer in the intervertebral discspace, the height of the variable lordotic interbody spacer may varyfrom unexpanded to fully expanded.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention willbecome more fully apparent from the following detailed description, theappended claims, and the accompanying drawings in which like referencenumerals identify similar or identical elements.

FIG. 1 shows an exploded top front view of a variable lordotic interbodyspacer with separated elements including a face plate, superior andinferior endplates, actuation frame and actuation screw in accordancewith one embodiment;

FIG. 2 shows a top perspective rear view of the variable lordoticinterbody spacer of FIG. 1 in a collapsed position;

FIG. 3 shows a right side view of the variable lordotic interbody spacerof FIG. 1 in the collapsed position;

FIG. 4 shows a top perspective rear view of a variable lordoticinterbody spacer of FIG. 1 in an open or expanded position;

FIG. 5 shows a right side of the variable lordotic interbody spacer ofFIG. 1 in the open or expanded position;

FIG. 6 shows a rear view of the rear face of the face plate of thevariable lordotic interbody spacer of FIG. 1;

FIG. 7 shows a front view of the front face of the face plate of thevariable lordotic interbody spacer of FIG. 1;

FIG. 8 shows the blocking screws, the actuation screw, and the screwretainer plate as positioned in the front face of the face plate of thevariable lordotic interbody spacer of FIG. 1;

FIG. 9 shows a top view of the superior endplate of the variablelordotic interbody spacer of FIG. 1;

FIG. 10 shows a bottom view of the superior endplate of the variablelordotic interbody spacer of FIG. 1;

FIG. 11 shows a bottom view of the inferior endplate of the variablelordotic interbody spacer of FIG. 1;

FIG. 12 shows a top view of the inferior endplate of the variablelordotic interbody spacer of FIG. 1;

FIG. 13 shows a top front view of the actuation frame of the variablelordotic interbody spacer of FIG. 1;

FIG. 14 shows a bottom rear view of the actuation frame of the variablelordotic interbody spacer of FIG. 1;

FIG. 15 shows a perspective view of a subassembly formed of the faceplate and the actuation frame of the variable lordotic interbody spacerof FIG. 1;

FIG. 16 shows another perspective view of a subassembly formed of theface plate, inferior endplate and the actuation frame of the variablelordotic interbody spacer of FIG. 1;

FIG. 17 shows a retaining hinge interface of the rear face of the faceplate of the variable lordotic interbody spacer of FIG. 1;

FIG. 18 shows a center-line axis, cutaway right side view of thevariable lordotic interbody spacer of FIG. 1 showing the operation ofthe actuation screw to the collapsed position;

FIG. 19 shows a center-line axis, cutaway right side view of thevariable lordotic interbody spacer of FIG. 1 showing the operation ofthe actuation screw to the open position;

FIG. 20 shows a right-side arm, cutaway right side view of the variablelordotic interbody spacer of FIG. 1 showing the operation of theactuation screw to the collapsed position;

FIG. 21 shows a right-side arm, cutaway right side view of the variablelordotic interbody spacer of FIG. 1 showing the operation of theactuation screw to the open position; and

FIG. 22 shows a perspective view of the front face of the face plateincluding bone screws of the variable lordotic interbody spacer of FIG.1.

DETAILED DESCRIPTION

In accordance with the described embodiments, a variable lordoticinterbody spacer includes: a face plate, superior and inferior endplatescoupled to the face plate via a hinge, an actuation frame between theendplates, and an actuation screw. The face plate includes actuation andstabilizer channels. Each of the endplates has endplate arms coupled byan endplate base, and includes actuation ramp recesses. The actuationframe includes frame arms coupled by a frame base in a generallyU-shaped configuration, each actuation frame arm having a stabilizerfeature passing through a corresponding stabilizer channel and havingactuation ramp pins fitted to a corresponding ramp recesses. Theactuation screw passes through the actuation channel, with a headretained at the front surface and a threaded end coupled to theactuation frame. When operated, the actuation screw moves the actuationframe between the superior endplate and the inferior endplate to adjustan angle there between. A variable lordotic interbody spacer inaccordance with the described embodiments might allow for a surgeon toadjust the position of a patient's lordosis via adjustment of thelordotic angle in situ during an interbody fusion operation.

FIG. 1 shows an exploded perspective top front view of a variablelordotic interbody spacer 100 with separated elements including faceplate 10, superior endplate 11, inferior endplate 12, actuation frame13, and actuation screw 14 in accordance with an exemplary embodiment ofthe present invention. Face plate 10 includes front face 10 a, rear face10 b, top 10 c and bottom 10 d. As used herein, the term “face”generally refers to a particular surface that may have one or morefeatures thereon. Superior endplate 11 includes first arm 11 a, secondarm 11 b, generally U-shaped base 11 c, center housing 11 d, and recess11 e formed at the center of base 11 c. Inferior endplate 12 includesfirst arm 12 a, second arm 12 b, generally U-shaped base 12 c, centerhousing 12 d, and recess 12 e formed at the center of base 12 c.

Actuation frame 13 includes first arm 13 a, second arm 13 b, generallyU-shaped base 13 c, center core 13 d, and knob 13 e formed at the centerof base 13 c. Knob 13 e formed at the center of base 13 c might beconfigured so as to fit in recesses 11 e and 12 e, as shown in thefigures. Knob 13 e might be configured so as to fit in recesses 11 e and12 e to guide actuation frame 13 between superior endplate 11 andinferior endplate 12 to prevent sideways movement under force, as wellas to start to force superior endplate 11 and inferior endplate 12 apartwhen actuation screw 14 is operated, as described subsequently.Actuation screw 14 includes head 14 a, bottom, threaded end 14 b, andbody section 14 c. Actuation screw 14 is retained in face plate 10 byscrew plate retainer 200 fastened to front face 10 a.

Lordotic interbody spacer 100 includes blocking assemblies 17, 18 and 19comprising blocking screw screws 17 a, 18 a, and 19 a that might bethreadably inserted into corresponding blocking screw channels 17 b, 18b and 19 b, as described subsequently.

Superior endplate 11 and inferior endplate 12 are coupled to rear face10 b of face plate 10 via hinges 21 and 22, Hinge 21 includes pins 21 acoupling ears 21 b and 21 c of superior endplate 11 and inferiorendplate 12, respectively. Similarly, hinge 22 includes pins 22 a, andcoupling ears 22 b and 22 c of superior endplate 11 and inferiorendplate 12, respectively.

FIG. 2 shows a perspective top rear view of variable lordotic interbodyspacer 100 of FIG. 1 in a collapsed position. FIG. 3 shows a right sideof the variable lordotic interbody spacer 100 of FIG. 1 in the collapsedposition in accordance with an exemplary embodiment. As is evident, thesuperior endplate 11 and inferior endplate 12 are substantially incontact with one another. In particular, knob 13 e is sized andconfigured to fit in at least a portion of recesses 11 e and 12 e in thesuperior and inferior endplates 11, 12 such that the superior andinferior endplates 11, 12 have a minimum height. The knob 13 e may besubstantially flush with an outermost end of the superior and inferiorendplates 11, 12. In addition, the end of the superior and inferiorendplates 11, 12 designed to enter into the disc space may include atleast one angled surface, which serve to distract the adjacent vertebralbodies when the spacer 100 is inserted into the intervertebral space. Asbest seen in FIG. 3, there may be at least two opposing angled surfacesforming a generally wedge shape to distract the adjacent vertebralbodies when the spacer 100 is inserted into the intervertebral space.

FIG. 4 shows a perspective top rear view of the variable lordoticinterbody spacer 100 of FIG. 1 in an open or expanded position. As shownin FIG. 4 and compared to FIGS. 2 and 3, in an open or fully expandedposition, actuation frame 13 is moved toward the rear face 10 a of faceplate 10, separating superior endplate 11 and inferior endplate 12. Whenin the open position, a gap 30 is formed between superior endplate 11and inferior endplate 12. FIG. 5 shows a right side of the variablelordotic interbody spacer 100 of FIG. 1 in the open or fully expandedposition. As shown in FIG. 5, when in the open position, gap 30 formedbetween superior endplate 11 and inferior endplate 12 creates an angle ϕbetween superior endplate 11 and inferior endplate 12. As such the upperand lower contact surfaces of the superior and inferior endplates 11,12, respectively, do not maintain a parallel configuration. Instead, theupper and lower contact surfaces of the superior and inferior endplates11, 12 are angled to align with corresponding patient anatomy.Consequently, angle ϕ between superior endplate 11 and inferior endplate12 allows for a surgeon to adjust the position of a patient's lordosisvia adjustment of the lordotic angle. As the actuation frame 13 is drawnback, the angle ϕ between superior endplate 11 and inferior endplate 12increases. In other words, as the actuation frame 13 insets a distancefrom the end of the spacer 100, the angle ϕ between superior endplate 11and inferior endplate 12 increases causing a greater degree ofseparation between the ends of the superior and inferior endplates 12and a greater angle ϕ and larger gap 30. Although shown in FIGS. 4 and 5in a fully expanded configuration with a maximum angle ϕ, it iscontemplated that the spacer 100 does not have to actuated to the fullyexpanded state. Rather, the height of the spacer 100, the angle ϕ, andthe gap 30 may be optimized to any suitable position from the fullycollapsed to fully expanded positions and anywhere in between.

FIG. 6 shows a perspective view of the rear face 10 b of face plate 10of FIG. 1. Rear face 10 b includes stabilizer channels 15 and 16, andactuation channel 20. Stabilizer channels 15 and 16 are sized andconfigured to receive first arm 13 a and second arm 13 b, respectively,of actuation frame 13. Stabilizer channels 15 and 16, first arm 13 a,and second arm 13 b are generally configured so as to be keyed, therebyguiding and preventing rotational movement of first arm 13 a and secondarm 13 b when subject to force. In particular, as shown in FIG. 6,stabilizer channels 15 and 16 may be provided with a substantiallyplus-shaped recess, which are sized and configured to receive acorresponding t-shaped extension on arms 13 a, 13 b of the actuationframe 13. The other portion of the plus-shaped recess may receive pins21 a and 22 a (best seen in the exploded view in FIG. 1), respectively.Preferably, the stabilizer channels 15 and 16 and correspondingextensions on arms 13 a, 13 b permit movement of the actuation frameduring expansion and contraction of the spacer 100.

Also as shown in FIG. 6, actuation channel 20 passes through face plate10 and may extend through protrusion 60. Protrusion 60 is shown havingholes 38 (hole 38 a shown, with hole 38 b, not shown, on opposite sideof protrusion 60) to receive retaining pins 21 a and 22 a of hinges 21and 22, thereby coupling superior endplate 11 and inferior endplate 12to rear face 10 b of face plate 10. Rear face 10 b might be configuredwith upper and lower tapered walls 35 a and 35 b, respectively, toprovide clearance for hinges 21 and 22.

FIG. 7 shows a perspective view of the front face 10 a of the face plate10 of variable lordotic interbody spacer 100 of FIG. 1. In order for auser to hold variable lordotic interbody spacer 100 with a tool (notshown in the figures), face plate 10 might be provided with one or morekeyed holes 36, shown as holes 36 a, 36 b, and 36 c, and tapped hole 37.Keyed holes 36 a, 36 b, and 36 c are keyed to corresponding features ofthe tool so as to hold spacer 100 without movement and keep variablelordotic interbody spacer 100 steady. Tapped hole 37 may be provided toallow a corresponding threaded or tapered element of the tool to befixed to front face 10 a of the variable lordotic interbody spacer 100.

FIG. 8 shows blocking screw assemblies 17, 18 and 19 includingcorresponding blocking screws 17 a, 18 a and 19 a, and blocking screwchannels 17 b, 18 b and 19 b as positioned in front face 10 a of faceplate 10 of variable lordotic interbody spacer 100. FIG. 8 also showsbone screw channels 40, 41, 42, and 43 which allow passage of bonescrews through variable lordotic interbody spacer 100 to fix spacer 100to a patient's vertebrae (spine). Projections or eyebrows in top 10 cand bottom 10 d of the face plate 10 may be provided. The bone screwchannels 40, 41, 42, and 43 may be provided at an angle to allow for thebone screws to be secured to adjacent upper and lower vertebrae,respectively, and to provide for maximum screw purchase into thevertebrae. The bone screws may be any suitable screws known in the artincluding fixed or variable angle. As shown, when blocking screws 17 a,18 a and 19 a are inserted to full depth in blocking screw channels 17b, 18 c and 19 d, blocking screw heads 17 c, 18 c and 19 c cover aportion of bone screw channels 40, 41, 42, and 43, allowing forretention of bone screws in bone screw channels 40, 41, 42, and 43(e.g., to prevent bone screws from working themselves out of variablelordotic interbody spacer 100).

FIG. 9 shows a top perspective view of superior endplate 11 of variablelordotic interbody spacer 100 of FIG. 1. As shown in the figure, thevolume (cavity) between first arm 11 a and center housing 11 d, and thevolume (cavity) between second arm 11 b and center housing 11 d, bothbounded by base 11 c and rear face 10 b of face plate 10, form graftwindow regions 45. Graft window regions 45 allow for insertion of graftmaterial within variable lordotic interbody spacer 100. The windowregions 45 may be configured for receiving and retaining one or morebone graft materials to promote fusion of the adjacent vertebral bodies.For example, cadaveric bone, autologous bone, bone slurry, BMP, or othersimilar materials, may enhance tissue growth within the intervertebralspace.

FIG. 10 shows a bottom of superior endplate 11 of variable lordoticinterbody spacer 100 of FIG. 1 including actuation ramp recesses 46 and47. While FIG. 10 is described having two ramp recess areas per armsurface, the invention is not limited and one skilled in the art mightemploy more or less ramp recess areas per arm surface. Each ramp recessarea of actuation ramp recesses 46 and 47 includes a ramp at its bottom,with each ramp recess area becoming shallower toward the ends of arms 11a and 11 b coupled to rear face 10 b of face plate 10 (not shown in FIG.10) and deeper toward base 11 c. Each ramp recess area of actuation ramprecesses 46 and 47 is bounded by a corresponding wall stop (wall stops48 and 49) formed within first arm 11 a and second arm 11 b toward base11 c. Also shown in FIG. 10, center housing 11 d includes a hollowedarea on the bottom forming half of actuation screw receptacle channel120, described subsequently.

FIG. 11 shows a perspective bottom view of inferior endplate 12 ofvariable lordotic interbody spacer 100. Inferior endplate 12 includesactuation ramp recesses 50 and 51 with corresponding stop walls 52 and53, respectively. FIG. 12 shows atop of inferior endplate 12 of variablelordotic interbody spacer 100 of FIG. 1, and shows graft window regions45 for graft material. Top and bottom of inferior endplate 12 includesimilar features to, and are similarly configured and formed as,corresponding top and bottom of superior endplate 11, so furtherdetailed description is omitted herein.

FIG. 13 shows a top rear surface of actuation frame 13 of variablelordotic interbody spacer 100 of FIG. 1. As shown, the top surfaceincludes stabilizers 26 and 27, and actuation ramp pins 66 and 67. Inparticular, each of stabilizers 26 and 27 is formed by a verticalprotrusion on the top surface of actuation frame 13 along the axis ofand at the corresponding ends toward face plate 10 of first arm 13 a andsecond arm 13 b, respectively, and is keyed with the correspondingstabilizer channel within face plate 10, as described previously. Thevertical protrusion of each stabilizer 26 and 27 may be tapered alongthe corresponding arm depending on the embodiment. In particular, thestabilizers 26 and 27 may have a greatest height at the outermost end ofarms 13 a and 13 b of the frame 13 and narrowest at a distance alongarms 13 a and 13 b. The ramped protrusions of stabilizers 26 and 27 mayextend along a portion of the distance of arms 13 a and 13 b (e.g.,about half way) or the entire distance of the frame 13.

Further, FIG. 13 shows actuation ramp pins 66 and 67, which are discretevertical protrusions on the top surface of actuation frame 13perpendicular to the axis of and at the corresponding ends toward base13 c of first arm 13 a and second arm 13 b. Actuation ramp pins 66 and67 are positioned on the top surface of actuation frame 13 so as to fitand move within corresponding actuation ramp recesses 46 and 47.Actuation ramp pins 66 and 67 each comprise two separate pins, shown as66 a and 66 b, and 67 a and 67 b, respectively, though one skilled inthe art might extend the teachings herein to employ a single actuationramp pin, or three or more actuation ramp pins, depending on theembodiment.

FIG. 14 shows a bottom view of actuation frame 13, which bottom surfacealso includes stabilizers 26 and 27 and actuation ramp pins 66 and 67.The actuation frame 13 also includes actuation screw receptacle 13 dformed at the interior of base 13 c and opposite to knob 13 e. Actuationscrew receptacle 13 d includes threaded hole 55 sized and configured toreceive threaded base 14 b of actuation screw 14 (not shown in FIG. 14).The outer surface of actuation screw receptacle 13 d may be formed in ashape to move in a restricted manner within actuation screw receptaclechannel 120 formed by hollowed areas of center housings 11 d and 12 d(not shown in FIG. 14).

Since the opposite, bottom front and rear surfaces of actuation frame 13include similar features to, and are similarly configured and formed as,corresponding top front and rear surfaces of actuation frame 13 shown inFIG. 13, detailed description of the bottom front and rear surfaces ofactuation frame 13 is omitted herein.

FIGS. 15, 16 and 17 show additional detail of the spacer 100. FIG. 15shows a subassembly formed of face plate 10 and actuation frame 13 andillustrates the coupling of face plate 10 to actuation frame 13 viathreaded end 14 b of actuation screw 14, as well as the insertion ofstabilizers 26 and 27 into corresponding stabilizer channels 15 and 16,respectively. FIG. 16 shows detail on the formation of hinges 21 and 22on rear face 10 b of face plate 10 of the variable lordotic interbodyspacer 100. In particular, FIG. 16 shows the subassembly of FIG. 15formed with the added inferior endplate 12, showing tabs 21 c and 22 cfastened into the hinges 21 and 22 by pins 21 a and 22 a, respectively.FIG. 17 shows a retaining hinge interface of rear face 10 b of faceplate 10 showing pin recesses 38 a-38 d for receiving pins 21 a and 22 a(best seen in the exploded view in FIG. 1), respectively.

Operation of the variable lordotic interbody spacer 100 of FIG. 1 is nowdescribed with respect to FIGS. 18 through 21.

FIG. 18 shows a center-line axis, cutaway right side view of thevariable lordotic interbody spacer 100 showing the operation ofactuation screw 14, with the spacer 100 in the collapsed position.Starting in the collapsed position, as actuation screw 14 is rotatedclockwise, threaded end 14 b rotates in threaded hole 55 of actuationscrew receptacle 13 d. Since head 14 a is retained by screw retainerplate 200, actuation screw 14 does not change position relative to faceplate 10 other than to rotate, which exerts a pulling force on actuationscrew receptacle 13 d. Consequently, actuation frame 13 is drawn backtoward face plate 10, forcing superior endplate 11 and inferior endplate12 apart. Superior endplate 11 and inferior endplate 12 are coupled torear face 10 b of face plate 10 via hinges 21 and 22, so these armendpoints do not move, but rather rotate about the hinge pins.

FIG. 19 shows a center-line axis, cutaway right side of the variablelordotic interbody spacer 100 showing the operation of the actuationscrew 14 to move the spacer 100 to the open or expanded position.Consequently, in the open position shown in FIG. 19, the gap 30 isformed at respective bases between superior endplate 11 and inferiorendplate 12, creating the angle ϕ between superior endplate 11 andinferior endplate 12 (shown in FIG. 5). As shown in FIG. 19, the knob 13e of the frame 13 is inset into the body of the spacer 100. As theactuation screw 14 is rotated, the actuation frame 13 is drawn towardthe face plate 10, the angle ϕ between superior endplate 11 and inferiorendplate 12 becomes larger and the gap 30 increases to create a greaterangle between the superior endplate 11 and inferior endplate 12.

FIG. 20 shows a right-side arm, cutaway right side of the variablelordotic interbody spacer 100 showing actuation screw 14 in thecollapsed position, and FIG. 21 shows the right-side arm, cutaway rightside of the variable lordotic interbody spacer 100 showing the operationof actuation screw 14 to the open or expanded position. Initially, asseen in FIG. 20, endplates 11 and 12 are closed as action ramp pins 46are at the bottom of ramp recesses 67 against wall stops 48 and 52. Asactuation screw 14 is rotated in a first direction (e.g., clockwise),endplates 11 and 12 are forced open as action ramp pins 46 ride up theramps at the bottom of ramp recesses 46 and 50. As a result, thesuperior endplate 11 and inferior endplate 12 are separated from oneanother as shown in FIG. 21.

FIG. 22 shows the front face 10 a of the face plate 10 including bonescrews 70, 71, 72 and 73 in corresponding bone screw channels 40, 41, 42and 43. As shown, blocking screw assemblies 17, 18 and 19 operate toretain bone screws 70, 71, 72 and 73 in corresponding bone screwchannels 40, 41, 42 and 43. After the bone screws 70, 71, 72 and 73 havebeen inserted through the corresponding bone screw channels 40, 41, 42and 43, the blocking assemblies 17, 18, and 19 can be rotated to blockand prevent the bone screw from inadvertently backing out. Inparticular, blocking screw assembly 17 blocks bone screw 70; blockingscrew assembly 18 blocks bone screws 71 and 72; and blocking screwassembly 19 blocks bone screw 73. Thus, the blocking screw assemblies17, 18, and 19 operate to prevent the respective bone screws 70, 71, 72,and 73 from backing out of the face plate 10 once implanted in thevertebrae. Although not shown, the superior and inferior endplates 11and 12 may optionally be provided with teeth or other projections whichcan engage or penetrate body tissue to reduce a likelihood of migrationof spacer 100 after implantation. With these features, the spacer 100can advantageously serve as a standalone spacer without the need foradditional fixation.

In accordance with the invention, implants of various sizes may beprovided to best fit the anatomy of the patient. The desired degree ofexpansion may be selected to provide for a natural lordosis, or acorrective lordosis, for example, of from 0° to 6° for a cervicalapplication, or from 3°-16° for a lumbar application, although muchdifferent values may be advantageous for other joints. Lordotic anglesmay also be formed by shaping one or both of endplates 11, 12 to haverelatively non-coplanar surfaces. Spacers 100 may be implanted withinany level of the spine, and may also be implanted in other joints of thebody, including joints of the hand, wrist, elbow, shoulder, hip, knee,ankle, or foot.

Reference herein to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment can be included in at least one embodiment of theinvention. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment, nor are separate or alternative embodiments necessarilymutually exclusive of other embodiments. The same applies to the term“implementation.”

As used in this application, the word “exemplary” is used herein to meanserving as an example, instance, or illustration. Any aspect or designdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects or designs. Rather, use ofthe word exemplary is intended to present concepts in a concretefashion.

Additionally, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or”. That is, unless specified otherwise, or clearfrom context, “X employs A or B” is intended to mean any of the naturalinclusive permutations. That is, if X employs A; X employs B; or Xemploys both A and B, then “X employs A or B” is satisfied under any ofthe foregoing instances. In addition, the articles “a” and “an” as usedin this application and the appended claims should generally beconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form.

Although the subject matter described herein may be described in thecontext of illustrative implementations to process one or more computingapplication features/operations for a computing application havinguser-interactive components the subject matter is not limited to theseparticular embodiments. Rather, the techniques described herein can beapplied to any suitable type of user-interactive component executionmanagement methods, systems, platforms, and/or apparatus.

Unless explicitly stated otherwise, each numerical value and rangeshould be interpreted as being approximate as if the word “about” or“approximately” preceded the value of the value or range.

The use of figure numbers and/or figure reference labels in the claimsis intended to identify one or more possible embodiments of the claimedsubject matter in order to facilitate the interpretation of the claims.Such use is not to be construed as necessarily limiting the scope ofthose claims to the embodiments shown in the corresponding figures.

It should be understood that the steps of the exemplary methods setforth herein are not necessarily required to be performed in the orderdescribed, and the order of the steps of such methods should beunderstood to be merely exemplary. Likewise, additional steps may beincluded in such methods, and certain steps may be omitted or combined,in methods consistent with various embodiments of the present invention.

Also for purposes of this description, the terms “couple,” “coupling,”“coupled,” “connect,” “connecting,” or “connected” refer to any mannerknown in the art or later developed in which energy is allowed to betransferred between two or more elements, and the interposition of oneor more additional elements is contemplated, although not required.Conversely, the terms “directly coupled,” “directly connected,” etc.,imply the absence of such additional elements.

Further, the term “comprises or includes” and/or “comprising orincluding” used in the document means that one or more other components,steps, operation and/or existence or addition of elements are notexcluded in addition to the described components, steps, operationand/or elements.

No claim element herein is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or “step for.”

It is understood that various changes in the details, materials, andarrangements of the parts which have been described and illustrated inorder to explain the nature of this invention may be made by thoseskilled in the art without departing from the scope of the embodimentsof the invention as encompassed in the following claims.

We claim:
 1. An apparatus for enabling a spinal fusion treatment andincluding a variable lordotic interbody spacer, the apparatuscomprising: a superior endplate; an inferior endplate; a face platehaving an actuation channel, the face plate coupled to the superior endplate and the inferior endplate; an actuation frame positioned betweenthe superior endplate and the inferior endplate; and an actuation screwconfigured to be received in the actuation channel, wherein theactuation screw is further configured to move the actuation framebetween the superior endplate and the inferior endplate to adjust anangle formed there between, and wherein the actuation screw isconfigured to be retained in the face plate by a screw plate retainer.2. The apparatus of claim 1, wherein stabilizer channels are formed inthe face plate and each stabilizer channel is configured to receive aframe arms of the actuation frame.
 3. The apparatus of claim 1, wherein,when rotated, the actuation screw moves the actuation frame toward theface plate to adjust the angle formed between the superior and inferiorendplates.
 4. The apparatus of claim 1, further comprising at least oneblocking assembly formed on a front surface of the face plate, eachblocking assembly comprising a blocking screw and a blocking screwchannel, wherein the blocking assembly allows for threaded insertion ofthe blocking screw into the corresponding blocking screw channel.
 5. Theapparatus of claim 4, wherein one blocking assembly is located adjacentto the head of the actuation screw, wherein, when tightened, theblocking screw of the one blocking assembly prevents the operation ofthe actuation screw.
 6. The apparatus of claim 4, further comprising atleast one bone screw channel formed through the face plate between thefront and rear surfaces, wherein one blocking assembly is locatedadjacent to a corresponding bone screw channel, and wherein, whentightened, the blocking screw of the one blocking assembly retains abone screw in the corresponding bone screw channel.
 7. The apparatus ofclaim 1, wherein each of the superior endplate and the inferior endplatehas first and second endplate arms coupled by an endplate base, each ofthe superior endplate and inferior endplate further includes a centerhousing formed between and in parallel with each corresponding endplatearm and coupled at one end to the corresponding endplate base, thesuperior endplate and the inferior endplate center housings forming areceptacle channel in between, wherein the receptacle of the actuationframe is guided by the receptacle channel when the actuation frame moveswith respect to the face plate.
 8. The apparatus of claim 1, furthercomprising at least one tool keying recess and at least one tappedrecess formed on the front surface of the face plate, wherein the atleast one tool keying recess and the at least one tapped recess areformed so as to lock the apparatus to a corresponding tool.
 9. Theapparatus of claim 1, wherein each endplate arm is coupled to a rearsurface of the face plate via a hinge opposite from the base, andwherein the rear surface of the face plate includes a protrusion havingthe actuation channel passing through and guiding the body of theactuation screw, wherein the protrusion is further coupled to the hinge.10. The apparatus of claim 9, wherein the hinge comprises tabs locatedon an end of each endplate arm coupled to the rear surface of the faceplate via pins, wherein the tabs are fastened, via the pins, to the rearsurface of the face plate at corresponding pin recesses.
 11. Theapparatus of claim 10, wherein the rear surface of the face plate isformed with a tapered wall to provide clearance for the hinge.
 12. Theapparatus of claim 1, wherein each of the superior endplate and theinferior endplate have a recess to receive a knob formed on theactuation frame.
 13. The apparatus of claim 1, wherein an area insidethe superior endplate, the inferior endplate, and the actuation frameform graft window regions, the graft window regions allowing forinsertion of graft material within the variable lordotic interbodyspacer.
 14. A standalone variable lordotic interbody spacer configuredto be implanted between two adjacent vertebrae comprising: a face platehaving an actuation channel and a stabilizer channel formed through aportion of the face plate, the stabilizer channel having a plus-shapedrecess; a superior endplate coupled to the face plate; an inferiorendplate coupled to the face plate; an actuation frame positionedbetween the superior endplate and the inferior endplate, the actuationframe having an arm configured to be received in the plus-shaped recess;and an actuation screw configured to be received in the actuationchannel, wherein the actuation screw is further configured to move theactuation frame between the superior endplate and the inferior endplateto adjust an angle formed there between.
 15. The spacer of claim 14,wherein the actuation frame includes actuation ramp pins in the form ofdiscrete vertical protrusions on top and bottom surfaces of theactuation frame.
 16. The spacer of claim 14, wherein the actuation ramppins extend perpendicular from the first and second frame arms.
 17. Thespacer of claim 14, wherein, when in the expanded position, a gap isformed between superior endplate and inferior endplate.
 18. The spacerof claim 14, wherein, when rotated, the actuation screw moves theactuation frame toward the face plate to adjust an angle formed betweenthe superior and inferior endplates.